STRUCTURAL, SURFACE MORPHOLOGY, OPTICAL AND ELECTRICAL INVESTIGATION OF CdSe THIN FILMS

Cadmium Selenide (CdSe) thin films were synthesized by chemical bath deposition (CBD) method. The XRD, SEM, UV-Visible absorption spectrum, dielectric studies and photoconductivity measurements were used to characterize the CdSe films. The X-ray diffraction (XRD) is used to examine the structure of CdSe thin film. The surface morphology of the film was analyzed using Scanning Electron Microscopy (SEM) and Atomic Force Microscope (AFM). The optical properties were studied using the UV-Visible absorption spectrum. Optical constants such as band gap, refractive index, reflectance, extinction coefficient and electric susceptibility were determined from UV-Visible absorption spectrum. The dielectric studies of CdSe thin films were studied in the different frequency and different temperatures. In addition, the plasma energy of the valence electron, Penn gap or average energy gap, the Fermi energy and electronic polarizability of the CdSe thin films have been also determined. The AC electrical conductivity measurements reveal that the conduction depends on both the frequency and the temperatures. The temperature dependent conductivity study confirmed the semiconducting nature of the films. Photoconductivity measurements are carried out in order to reveal the positive photoconductivity of the CdSe Thin films.